Background: The Pilates method has been used to improve function and reduce pain in patients with chronic nonspecific low back pain, although there is little scientific evidence that describes its efficacy.

Objective: The purpose of this study was to investigate the effectiveness of the addition of modified Pilates exercises to minimal intervention in patients with chronic low back pain.

Design: A randomized controlled trial was conducted.

Setting: The study was done in an outpatient physical therapy department in Brazil.

Patients: Eighty-six patients with chronic nonspecific low back pain participated in the study.

Intervention: All participants received an education booklet containing information about low back pain and were randomly allocated to receive 12 sessions, over 6 weeks, of exercises based upon Pilates principles (n=43) or of education alone (n=43).

Measurements: Primary outcomes were pain intensity and disability measured at 6 weeks and 6 months. Secondary outcomes were patient-specific functional disability, global impression of recovery, and kinesiophobia measured at 6 weeks and 6 months. All outcomes were measured by a blinded assessor in all time points.

Results: There was no loss to follow-up at any of the time points. Improvements were observed in pain (mean difference=2.2 points, 95% confidence interval [CI]=1.1 to 3.2), disability (mean difference=2.7 points, 95% CI=1.0 to 4.4), and global impression of recovery (mean difference=-1.5 points, 95% CI=-2.6 to -0.4) in favor of the Pilates group after intervention, but these differences were no longer statistically significant at 6 months.

Limitations: Treatment provider and participants could not be blinded to the interventions.

Conclusions: The addition of modified Pilates exercises to an educational booklet provides small benefits compared with education alone in patients with chronic nonspecific low back pain; however, these effects were not sustained over time.